Organic materials are often susceptible to oxidation, resulting in undesirable effects such as objectionable odor, sludge formation, loss of strength, development of or increased acidity, and the like.
Numerous compounds have been found to reduce oxidative susceptibility of various organic materials. Well known antioxidant compounds include various divalent sulfur-containing compounds, certain aromatic amines and phenolic compounds and derivatives. Certain hindered phenolic compounds have been described as being particularly suitable as antioxidants for organic materials, especially on a cost-performance basis. However, not all compounds of this type provide antioxidancy. Furthermore, numerous compounds of this type possess other properties which are objectionable. It is also desirable that lubricating and fuel compositions are essentially free of chlorine. Preferably, they contain no chlorine.
Davis, et al in U.S. Pat. No. 2,538,355 describes 2,2'-alkylene bis-4,6-dialkyl phenols of the formula ##STR2## wherein R.sub.1 is a straight chain alkyl radical of from 1 to 3 carbon atoms and R.sub.2 is a tertiary alkyl radical of from 4 to about 8 carbon atoms as rubber stabilizers.
Stevens et al in U.S. Pat. No. 2,515,906 describes bis (hydroxyphenyl) compounds of the formula ##STR3## wherein R.sub.1 is selected from the class consisting of secondary and tertiary butyl groups and R.sub.2 is selected from the class consisting of alkyl, cycloalkyl, aryl, aralkyl and alkaryl groups as additives for oil. In U.S. Pat. No. 2,570,402, Stevens et al describes oils and gasolines containing these compounds.
Knowles et al in U.S. Pat. No. 2,830,025 describes lubricating compositions containing monomeric condensation products of alkylated phenols with carbonyl-containing compounds. The condensation products are represented by the formulae ##STR4## wherein R is a hydrocarbon radical which may be alkyl, aryl, aralkyl or alkaryl, R.sub.1 is tertiary alkyl, R.sub.2 is a hydrogen or an alkyl radical and R.sub.2 is a hydrocarbon radical such as R. R is preferably alkyl having from 1 to 12 carbons, R.sub.2 is tertiary alkyl containing 4 to 12 carbons, R.sub.2 is hydrogen or methyl and R.sub.3 is preferably alkyl or halogenated alkyl having up to 7 carbon atoms.
It has been found that in certain applications, many of the bis-t-alkyl phenols of the art are ineffective or only marginally effective. Lubricating oils require antioxidants that are soluble or dispersable in oil in amounts effective to provide antioxidancy. High temperature applications require additives that are stable at the elevated temperatures and which are substantially non-volatile under conditions of use. By substantially non-volatile is meant that at least 50%, preferably at least 75% and more preferably at least 90% by weight of the additive remains in the lubricant under conditions of use.
For fuels, solubility in the fuel is also required.
For use in other applications such as resins, rubbers, waxes, etc. it is generally desirable that the compounds do not impart pronounced color to the substrate and also are substantially non-volatile.
Therefore, it is an object of this invention to provide novel phenolic compositions that will impart useful and desirable properties to organic materials.
It is a further object of this invention to provide novel organic compositions containing the novel phenolic compositions of this invention.
A further object is to provide novel lubricant and fuel compositions containing the novel phenolic compounds of this invention.
Other objects will be apparent to those skilled in the art upon review of the present specification.